As use of scarecrows does not work well for the purpose of scaring away wild animals or birds, more and more farm holders are adopting electric fences. Although considered one of the most effective ways to keep wild animals away, electric fencing is challenged by a few shortcomings, such as failure to respond to birds and high costs for installation and maintenance.
Birds' excreta, not only insanitary but even corrosive as well, may do severe damage to, e.g., food storage facilities.
Boar, water deer, or other pest wild animals are recently in sharp overpopulation, harming farmlands or graveyards. Boar are nocturnal animals that only come out at night to forage for food. Water deer are active both day and night. Such pest animals are impossible to repel only with alert sirens or lighting devices.
Introduced were several approaches for repelling or deterring wild animals. Korean Utility Model Registration No. 20-0408878 discloses a wild animal repelling device that keeps away animals with light radiations, but not with sounds. This device, however, is helpless with day-active animals. Further, the device is limited in effect by its design to reflect light only in some directions, not all. This type of devices adopt only light beaming for animal repelling, and to achieve an effect, many units of such device should be deployed in a target area.
Another conventional way is the use of alert sounds for repelling birds, an example of which is disclosed in Korean Utility Model Registration No. 20-0239741. The device set forth therein is limited in effect by repelling birds only by way of distressing sounds.
Some other types of wild animal repelling devices are equipped with a laser, which are used in airports or farms. For these devices to work properly, laser beams need to be aimed at the target pests.